DESCRIPTION: An inverse relationship between income and depression incidence has long been observed in specific contexts. This research proposes to explore racial, gender, and income-related disparities in both the incidence and in the treatment of depression in the U.S. population. The first goal of this research is to establish an inverse income/depression relationship in a nationally representative sample. At the same time, the research will address the question of how this link is mediated by race, gender and income. The question will be answered using highly flexible, non-parametric methods. Second, the research will answer the question of how the diagnosis and treatment of depression vary with underlying symptoms and with socio-economic status. The research will test the hypothesis that among U.S. adults with similar access to care, the diagnosis and treatment of depression varies with race, gender and income, even controlling for underlying symptom level. The analysis will use two rich, national, longitudinal data sets, and will employ two-stage, instrumental-variable statistical methods to control for reverse causality between symptom levels and treatment. The results of this research will be of major interest to health services researchers, to mental health providers and to policy-makers.